Decontamination methods are used in a broad range of applications and have used an equally broad range of sterilization agents. As used herein the term “decontamination” refers to processes, including, but not limited to, “deactivation of biocontamination,” “deactivation of chemical contamination,” “sterilization,” “disinfection,” and “sanitization.” Chemicals used to effect decontamination are interchangeably referred to herein as decontaminants or sterilants.
In recent years, systems have been developed that utilize a cold mist of a sterilant or decontaminant to deactivate rooms or spaces. Cold-mist systems typically introduce an atomized decontaminant or sterilant into a room or space to effect the decontamination. Most of these systems tend to be simple and do not precondition the air within the room or space before introducing the atomized sterilant or decontaminant therein. Existing cold-mist decontamination systems usually introduce a given amount of sterilant into a room or space based upon the volume of the room or space and do not take into account the capacity of the air within the room or space to hold the sterilant. In this respect, the amount of sterilant a room or space can hold without the sterilant condensing on surfaces within the room or space is a function of the temperature and the initial humidity level within the room or space. One problem with such a system, particularly if it utilizes atomized hydrogen peroxide, is that water has a higher vapor pressure than hydrogen peroxide. As a result, atomized water droplets will vaporize, i.e., evaporate, more quickly in a room or space than will atomized hydrogen peroxide droplets. Under certain conditions, liquid hydrogen peroxide having a 5% concentration of hydrogen peroxide can produce liquid droplets within the room or space having a hydrogen peroxide concentration of 38%, which is very corrosive and highly flammable.
The present invention provides a cold-mist hydrogen peroxide decontamination system that optimizes a decontamination cycle by evaluating the environmental conditions within a room or space and introducing an atomized hydrogen peroxide mist into the room or space at a level that will not condense on objects within the room or space.